Book excerpt: April and May of 1988 along the central California coast were characterized as a period of strong coastal upwelling produced by moderate to strong northwesterly winds present throughout the period. A product of this upwelling event was the manifestation of southward geostrophic currents which extended to a distance of approximately 50 km from the coast. From 08 to 11 May 1988, hydrographic surveying was conducted within the Monterey Bay. Internal waves, with amplitudes of up to 30 m were present throughout the period and effectively masked the mean signal, implying that averaging is essential to avoid aliasing. The current -- temperature -- depth (CTD) data were averaged to estimate the mean field during this time frame. Acoustic Doppler Current Profiler (ADCP) data, were also averaged. The mean flow field and dynamic topography implied anticyclonic surface flow with cyclonic flow at 200 m depth. ADCP derived mean flows compared favorably with geostrophic mean flow rate in all areas except one, the deep outflow region along the northern wall of the Canyon. Application of ocean models of boundary layer flow of the geostrophic mean field yielded flows similar to those described above. Wind stress experiments indicated that strong wind field may influence surface circulation in the Bay. Interactions between the coastal upwelling geostrophic jet and the Monterey Submarine Canyon is believed to have been a major mechanism responsible for the mean flow.